Crossover pipe size 2.25 or 2.5?
Crossover pipe size 2.25 or 2.5? Street driven 69 Camaro with a 6.0 LQ4, Precision 76/75 Tick Stage 2 cam and a 4l80, curious on the benefits or drawbacks of pipe size with this setup. Originally built it with 2.5 but due to overheating issues I am moving the turbo from the drivers side to the passenger side to eliminate some piping running in front of the engine and since I have to remake everything, figured I would ask.
Street driven 69 Camaro with a 6.0 LQ4, Precision 76/75 Tick Stage 2 cam and a 4l80, curious on the benefits or drawbacks of pipe size with this setup. Originally built it with 2.5 but due to overheating issues I am moving the turbo from the drivers side to the passenger side to eliminate some piping running in front of the engine and since I have to remake everything, figured I would ask.
I know you said 7675 but I'd build it on a T6 platform with 2.25" since you're redoing it.
An S475 can spool just as fast as a 7675 and make way more power with the larger turbine should you want more.
My Huron Speed T6 kit is 2.25" with an S484 and it lights off pretty fast.
Just sayin.
An S475 can spool just as fast as a 7675 and make way more power with the larger turbine should you want more.
My Huron Speed T6 kit is 2.25" with an S484 and it lights off pretty fast.
Just sayin.
I looked through that sticky and I was not able to find a definitive answer on which is better and why, and it was an old thread from 2013. With all the new technology in turbos thought maybe their would be something updated or real world experience.
02 Camaro SS sbe LS1, CNC 317 heads, turbo cam, six speed car, 2.5" merged hotside with a T4 7875 Turbonetics turbo, about 700whp on 14 lbs.
99 Camaro SS forged LS1, CNC 243 heads, FI cam, TH400, 2.25" divided hotside w/ a T6 S484, 743whp on 12 lbs with a slipping trans.
The divided T6 comes online faster than the T4 ever did and starts making positive manifold pressure around 3,500 rpm, the T4 was usually making positive pressure around 4000+rpm and up but wouldn't really make full boost until 3rd and 4th gear.
The T6 combo will make peak in first gear by 4,500ish rpm and carry it out until redline.
Go with the 2.25", it will flow more than you'll probably ever need but most importantly keep up the velocity in the pipe to hit the turbine harder, plus its easier to package and cheaper to build.
Trending Topics
I went with 2.25 myself. Billet BWs480, 5.3. Not sure if your going SS or Mild Steel but if Argon $$$ is like up here....
I wanna shoot myself in the face with how much I spent on argon so far and Im not done yet.
I wanna shoot myself in the face with how much I spent on argon so far and Im not done yet.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
I have a 5.3 and a VSRacing Billet wheel S480 T6 Flanged 1.32 A/R with the 102/92 split flange Turbine. When I was about to start fabbing the hotside, Forcefed indicated that if he were me, he'd use 2.25 piping going from the headers to the flange, keeping it divided until the flange. I did so and I'm very happy with the result. It starts making positive boost by 3,200 RPM and the top end rush is exhilarating. As others have input, the 2.25" is plenty of throughput to the turbo and is less expensive, easier to package.
I am just going to throw out a bomb, and see where it hits. Anybody done a 1' Crossover? The exhaust hole in the turbo is the biggest restriction, so why not?
That was supposed to say 1 inch, but oops.
That was supposed to say 1 inch, but oops.
Here's what I can offer, not quite apples to apples but better than nothing.
02 Camaro SS sbe LS1, CNC 317 heads, turbo cam, six speed car, 2.5" merged hotside with a T4 7875 Turbonetics turbo, about 700whp on 14 lbs.
99 Camaro SS forged LS1, CNC 243 heads, FI cam, TH400, 2.25" divided hotside w/ a T6 S484, 743whp on 12 lbs with a slipping trans.
The divided T6 comes online faster than the T4 ever did and starts making positive manifold pressure around 3,500 rpm, the T4 was usually making positive pressure around 4000+rpm and up but wouldn't really make full boost until 3rd and 4th gear.
The T6 combo will make peak in first gear by 4,500ish rpm and carry it out until redline.
Go with the 2.25", it will flow more than you'll probably ever need but most importantly keep up the velocity in the pipe to hit the turbine harder, plus its easier to package and cheaper to build.
02 Camaro SS sbe LS1, CNC 317 heads, turbo cam, six speed car, 2.5" merged hotside with a T4 7875 Turbonetics turbo, about 700whp on 14 lbs.
99 Camaro SS forged LS1, CNC 243 heads, FI cam, TH400, 2.25" divided hotside w/ a T6 S484, 743whp on 12 lbs with a slipping trans.
The divided T6 comes online faster than the T4 ever did and starts making positive manifold pressure around 3,500 rpm, the T4 was usually making positive pressure around 4000+rpm and up but wouldn't really make full boost until 3rd and 4th gear.
The T6 combo will make peak in first gear by 4,500ish rpm and carry it out until redline.
Go with the 2.25", it will flow more than you'll probably ever need but most importantly keep up the velocity in the pipe to hit the turbine harder, plus its easier to package and cheaper to build.
I'd imagine the 7875 would have spooled better with an auto but being a 2.5" merged hotside its tough to say how much better versus a divided T6 setup.
NA, that comparison is misleading. Nothing is probably better. 😋